Answers created by Truong-Son N.

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• Hydrogen bonding is of two types - t Intramolecular and intermolecular Am I right ?
  
• Which lanthanides are exceptions to the Aufbau principle?
  
• What is the effective atomic number of tetraaquadichlorochromium(II)?
  
• I do not understand this " rate of diffusion of gases is inversely proportional to the square root of their molar masses provided that pressure and temperature remain constant. ?
  
• How many micro states exist for a molecule?
  
• Draw #BF_3# and assign a point group. How many degrees of vibrational freedom does the molecule have?
  
• List examples of positive and negative ligands?
  
• What is the molarity of a #"KOH"# solution with relative density #0.0028# and #%"w/w" = 40%#? The molar mass of #"KOH"# is #"56.1056 g/mol"#.
  
• Is raffinose NOT a saccharide?
  
• Can someone help me please? I didn't do it right then I got it right. Thanks!
  
• Question #b41bf
  
• How do you find the rate of reaction given the rate constant and concentrations if you don’t have the time?
  
• Hello there! I think I would need some help for this one. Can you try helping me out please ? Thanks!
  
• What is the #n^(th)# derivative of # y(x) = e^x sinx #?
  
• Which of the following should occur when placing a certain amount of tetraphosphorus solid in the same container as dihydrogen gas, if #"8.0 mols"# of #"H"_2(g)# are present?
  
• What are positive and negative deviation with respect to ideal binary mixtures?
  
• Help with question 11 c guys ?
  
• For what values of x is #f(x)=x^3-e^x# concave or convex?
  
• Can salinity be negative?
  
• Which first-row transition metal has the most unpaired electrons?
  
• Why does nitrogen have a higher ionization energy than oxygen?
  
• Which one is the electron configuration of #"Fe"^(+)#? #[Ar] 3d^5 4s^1#, or #[Ar]3d^6#?
  
• I come in many colors. Although I have a cubic crystal stucture, I tend to break into octahedrons. It might surprise you that I have weak fluorescence. What am I?
  
• How does the length of the z-component of the net dipole moment of ammonia relate to the actual length of the dipole moment vector?
  
• Question #d6bce
  
• Which of the following is the correct expression for the rate of the following reaction? Note: not all species are gaseous. CuO(s) + H2S (g) <--> Cu(s) + H2O (g)
  
• A photon has a wavelength of 3.5 A0. Calculate its mass. (Planck's constant, h = 6.626 x 10-34 Js. Velocity of light = 3 x 108 m/s) What is de answer?
  
• How many electrons are found in a sample of dioxygen gas contained in a #"0.448 L"# container at STP?
  
• A system at equilibrium is placed under stress by adding more reactant. If this reaction has a small equilibrium constant (Keq), how will the addition of this stress affect the equilibrium of this system?
  
• For the reaction #"Fe"_2"O"_3 + 2"X" -> 2"Fe" + "X"_2"O"_3#, if #"79.847 g"# #"Fe"_2"O"_3# reacts with excess #"X"# (#FW = "159.691 g/mol"# for the iron(III) oxide) to yield #"50.982 g X"_2"O"_3# and #"55.847 g Fe"#, what is the identity of #"X"#?
  
• Why is there so much ozone?
  
• Find the sum of #1^2 - 2^2 + 3^2 - 4^2 + 5^2 - 6^2........#? ( Please find out the #n^(th) term and then use the sigma method)
  
• Graph 3 members of the family of curves that have f(x) = -x+1 as a common derivative. Help!?
  
• What are the things must be remember while studying adiabatic processes?
  
• A gas under a pressure of 74 mmHg and at a temperature of 75°C occupies a 500.0-L container. How many moles of gas are in the container?
  
• Why does more heat transfer take place in a reversible process than in a irreversible process?
  
• Which of these does Planck's constant depend on?
  
• Does an electron move from one allowed orbit to another only when it absorbs or emits a fixed amount of energy?
  
• Question #fcc68
  
• If the #"pH"# is #6.49# and the three values of #"pK"_a = 2.148, 7.199, 12.15# for phosphoric acid, what species dominates in solution?
  
• Question #51efc
  
• What is the mass of #"0.1 mols"# of electrons in #"amu"#?
  
• How do you find the four quantum numbers?
  
• #y(x,t) = Ce^(iomegax//c)e^(-iomegat) = Ce^(ialpha)#, where #alpha = (2pix)/lambda - 2pi nut#... Show that for standing waves, #y(x,t) = Asin((npix)/L)sin(2pin nu_0 t + delta)#? You may want to note the boundary conditions of a vibrating guitar string.
  
• What atomic number of an element "X" would have to become so that the 4th orbit around X would fit inside the 1st Bohr orbit of H-atom?
  
• What is the molarity of an aqueous NaOH solution containing 20 g of NaOH and 400 g of water?
  
• What is the oxidation state of zinc in #"ZnO"_2#?
  
• In a mass spectrum, will the mass of the ion always be the same as the mass of the molecule?
  
• Are gases denser than liquids and solids?
  
• Which of these complexes has the lowest-energy #d-d# transition band in a UV-Vis spectrum?
  
• Which of these transition metal complexes contain #3d^6# metals?
  
• Concentration questions about freezing point depression and osmolarity?
  
• Find the partial pressure in a solution containing ethanol and 1-propanol with a total vapor pressure of #"56.3 torr"#? The pure vapor pressures are #"100.0 torr"# and #"37.6 torr"#, respectively, and the solution has a mol fraction of #0.300# of ethanol.
  
• Which of these is the best Lewis acid?
  
• How do I draw the MO diagrams for #"O"_2^-# and #"CO"^(+)# and find out which one is paramagnetic?
  
• Which of the following reactions do square planar complexes undergo?
  
• What is the relationship between normality and molarity? Normality and molality? Mole fraction and molarity?
  
• How is #"CO"_2# nonpolar?
  
• What is the polar form of #( 0,0 )#?
  
• Explain associative interchange reactions? What is the mechanism?
  
• A certain first-order reaction has a rate of #"0.04 M/s"# after 10 seconds and #"0.03 M/s"# after 20 seconds. What is the half-life for this reaction?
  
• Why is aspirin considered to be a weak acid and how can you measure the exact pH?
  
• If #F(x)# and #G(x)# both solve the same initial value problem, then is it true that #F(x) = G(x)#?
  
• If the energy of an X-ray photon is #"100 keV"#, then if its wavelength matches that of the ejected core electron, what should be the kinetic energy of that electron?
  
• When #"11.6 g"# of citric acid reacts with excess sodium bicarbonate, what mass of #"CO"_2# is made in #"g"#? #MW = "44 g/mol"#
  
• What are bosons?
  
• Which of these frequencies is resonant with that of an ideal #"256 Hz"# tuning fork?
  
• What does #"mM"# mean?
  
• What is the difference between molecular mass and formula unit mass?
  
• Why do we use prefixes like nano, pico, kilo, and micro?
  
• Identify the Bronsted-Lowry acid and base in the reaction #"NH"_4^(+)(aq) + "H"_2"O"(l) -> "NH"_3(aq) + "H"_3"O"^(+)(aq)#? What is the conjugate base?
  
• How many structures are there for #"XeF"_5^(+)#?
  
• How do you name [Co(en)2CO3]Br?
  
• If #f(x) = P sin(7x) + Qcos(7x)# and #f'(x) = xsin(7x)#, find #int_(9)^(pi//7) xsin(7x)dx#?
  
• Why transition elements show tendency to form large number of complexes??
  
• Derive an expression for the fraction of dissociation of a diatomic gas molecule into two gaseous atoms?
  
• What is the distance of a #2s# electron from the nucleus of H atom?
  
• What should I know about a titration curve of strong base added into weak acid?
  
• Why is the election affinity of beryllium negative?
  
• Why is the first ionization energy of #"O"# lower than for #"N"#, but the second ionization energy for #"O"# higher?
  
• The reaction time in a laboratory setting is how many seconds?
  
• How many radial nodes are in a given atomic orbital as a function of #n# and #l#?
  
• A solution that contains #"13.2 g"# of solute in #"250 g"# of #"CCl"_4# freezes at #-33^@ "C"#. What is the FW of the solute? #T_f^"*"# of #"CCl"_4# is #-22.8^@ "C"# and its #K_f = -29.8^@ "C/m"#.
  
• How do you evaluate #0.606ln0.606 + 0.394ln0.394#?
  
• What is the Gibbs' free energy of formation for #"O"_2(g)#?
  
• What is the formal charge on the phosphate ion in #PO_3^-#?
  
• Find the ΔH° for the reaction? a) Fe2O3(s)+3CO2(g)→2Fe(s)+3CO2(g)
  
• How do the chemical potentials compare for the vapour and liquid phases at, below, and above the boiling point in a phase diagram?
  
• How do you solve 6x+5y=10 and 7x-3y=24?
  
• What volume must the final solution reach if you want to make a #"0.01 N"# oxalic acid solution in water using #"126 g"# of oxalic acid solid?
  
• If #sum_k a_n = sum_k (-2n^4 + 5n^2 - 3)/(n^11 - 9n^3 - 9)# and #sum_k b_n = sum_k 1/n^beta#, then for what value of #beta# could allow #a_n/b_n# to converge?
  
• In #"1200 g"# of a saturated (#"40 M"#) solution of #"Na"_2"SO"_4# in water at #20^@ "C"#, what is the mass of solute found within it?
  
• If the initial concentration of #"AB"# in #AB(g) -> A(g) + B(g)# is #"1.50 M"#, and #k = "0.80 M"^(-1)cdot"s"^(-1)#, what amount of time passes until the concentration becomes #1//3# of what it began as in this second-order decomposition?
  
• Which of these has nonzero orientation polarization? #"NH"_3#, #"BF"_3#
  
• How to you convert between pH, pOH, [H+] and [OH-]?
  
• Question #84ead
  
• At NTP, what is the mass of #"22.4 L"# of nitrogen gas?
  
• How do you write the orbital diagram for phosphate?
  
• The spin only magnetic moment value (in Bohr magneton units) of #Cr(CO)_"6"# is?
  
• What is the #"pH"# for an aqueous solution with #["H"^+] = 7.5 xx 10^(-3) "M"#?
  
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